KR20240027807A - electrochemical device - Google Patents

Abstract

An electrochemical device capable of maintaining good electrical connection and having excellent sealing properties is provided. The electrochemical element 1 includes a case 10 having a concave container 11 having a bottom portion 111 and a side wall portion 112 and a cover material 12 that covers the opening of the concave container 11; , a power generation element that has a laminate of the electrode layer 21, the electrode layer 22, and the solid electrolyte layer 23, and is accommodated in the inner space of the case 11 so that the bottom portion 111 and the electrode layer 21 face each other. (20) and a conductive plate (30) disposed between the electrode layer (22) and the cover material (12) on the opening side of the concave container (11). The concave container 11 has a plurality of support portions 115 on the inner peripheral surface of the side wall portion 112. The conductive plate 30 has a plurality of supported portions 31 corresponding to the positions of each supporting portion 115 at its edge end. With each supported portion 31 supported on the support portion 115, the power generation element 20 is moved toward the bottom 111 of the concave container 11 by the spring piece 33 of the conductive plate 30. It is pressurized.

Description

electrochemical device

This disclosure relates to an electrochemical device in which a power generation element is sealed within a case.

Conventionally, various batteries have been disclosed in which a power generation element is accommodated in an internal space formed by a concave container and a cover material covering the opening of the concave container.

Japanese Patent Application Laid-Open No. 2012-69508 (Patent Document 1) discloses an electrochemical cell with stable electrochemical properties. An electrochemical cell has a sealed container. The sealed container consists of a base member and a lid member. A storage space in which the electrochemical element (electrode body) is stored is formed between the two members. An elastic member that presses the electrochemical element is disposed between the lead member and the electrochemical element. Patent Document 1 is an elastic member, which is a leaf spring bent into a V-shape when viewed in cross section, a torsion bar unit that uses elastic restoring force resulting from torsion, or a concave that is turned over from the center toward the outer periphery. An embodiment using a diaphragm-shaped spring or the like formed in a curved shape is disclosed.

In addition, Japanese Patent Application Laid-Open No. 2010-56067 (Patent Document 2) describes a battery element having a first electrode, a solid electrolyte, and a second electrode, a metal case, a metal sealing plate, and a gasket interposed between them. A coin-type lithium secondary battery is disclosed that is encapsulated in a container and a conductive elastic body is disposed between the battery element and a metal case or a metal sealing plate. The conductive elastic body can pressurize the laminate at a pressure of 0.1 MPa or more and increase the contact surface pressure between the first electrode and the second electrode and the solid electrolyte. As a result, a decrease in current density can be suppressed.

Japanese Patent Laid-Open No. 2012-69508 Japanese Patent Laid-Open No. 2010-56067

However, in the electrochemical cell of Patent Document 1, in the embodiment in which the electrode body is pressed while the elastic member is positionally controlled by the lead member, when sealing the electrochemical cell, the lead member presses the elastic member. It is necessary to join the lead member and the base member. Therefore, there is a risk that the lead member is likely to tilt due to the reaction force from the elastic member, resulting in non-uniform joining of the lead member and the base member. Additionally, if the elastic member is not fixed to the lead member or electrode body, there is a risk that the elastic member may be misaligned during sealing. On the other hand, in an embodiment in which an elastic member (diaphragm-like spring) is engaged with a seal ring or a base member and the elastic member and the lead member are separated, the width from the center to the outer periphery in the height direction (the entire length of the spring) thickness) increases, and because the locking position of the spring becomes the outer periphery at the top in the height direction, a large gap is created between the lead member and the electrochemical element, including the gap between the elastic member and the lead member. Therefore, it becomes a factor that hinders the increase in capacity of the electrochemical cell.

In addition, in the coin-type lithium secondary battery of Patent Document 2, it is necessary to caulk the metal case so that the battery element is pressed with a certain or more pressing force by a conductive elastic body while generating an appropriate pressing force on the gasket. In particular, in a form in which only the central portion of the metal sealing plate presses the elastic body, it is difficult to generate a uniform pressing force throughout the entire gasket, and the sealing properties tend to deteriorate.

Therefore, the present disclosure aims to provide an electrochemical element that can maintain good electrical connection and has excellent sealing properties.

In order to solve the above problems, the present disclosure is structured as follows. That is, the electrochemical element related to the present disclosure includes a case having a concave container having a bottom and a side wall portion and a cover material covering the opening of the concave container, a first electrode layer sealed in the case and disposed on the bottom side, and It is provided with a power generation element having a second electrode layer disposed on the cover material side and an isolation layer disposed between the first electrode layer and the second electrode layer, and a conductive plate disposed between the power generation element and the cover material. The first electrode layer is electrically connected to a first conductive path leading from the inside of the case to the outside. The second electrode layer is electrically connected to a second conductive path extending from the inside of the case to the outside via a conductive plate. The conductive plate includes a flat portion facing the power generation element and a spring portion that rises from the flat portion to press the power generation element toward the bottom of the concave container, and is concave radially outward from the power generation element when viewed in plan. A gap is formed between the conductive plate fastened to the side wall of the mold container and the cover material.

According to the electrochemical device related to the present disclosure, good electrical connection can be maintained and excellent sealing properties can be obtained.

1 is a cross-sectional view showing an electrochemical element according to the first embodiment.
FIG. 2 is an external perspective view showing the concave container of the electrochemical element of FIG. 1.
Figure 3 is an external perspective view showing another concave container of an electrochemical element.
FIG. 4 is a plan view showing the electrochemical element of FIG. 1 (excluding the cover material and conductive plate).
Fig. 5 is a cross-sectional view showing a conductive plate according to Modification Example 1.
FIG. 6 is a perspective view showing the conductive plate of FIG. 5.
Fig. 7 is a plan view showing the conductive plate according to Modification Example 2.
Fig. 8 is a plan view showing the conductive plate according to Modification Example 3.
Fig. 9 is a cross-sectional view showing a conductive plate according to Modification Example 4.
Fig. 10 is a plan view showing the conductive plate according to Modification Example 5.
Fig. 11 is a plan view showing the conductive plate according to Modification Example 6.
Fig. 12 is a plan view showing the conductive plate according to Modification Example 7.
Fig. 13 is a plan view showing the conductive plate according to Modification Example 8.
Fig. 14 is a plan view showing the conductive plate according to Modification Example 9.
Fig. 15 is a cross-sectional view showing a conductive plate according to Modification Example 10.
FIG. 16 is a plan view showing the conductive plate of FIG. 15.
Fig. 17 is a cross-sectional view showing an electrochemical element according to the second embodiment.
Fig. 18 is a cross-sectional view showing an electrochemical element according to the third embodiment.
Fig. 19 is a cross-sectional view showing an electrochemical element according to the fourth embodiment.

(Configuration 1)

An electrochemical element related to an embodiment of the present disclosure includes a case having a concave container having a bottom and a side wall portion and a cover material that covers the opening of the concave container, and a first electrode layer sealed in the case and disposed on the bottom side. and a power generation element having a second electrode layer disposed on the cover material side and an isolation layer disposed between the first electrode layer and the second electrode layer, and a conductive plate disposed between the power generation element and the cover material. The first electrode layer is electrically connected to a first conductive path extending from the inside of the case to the outside. The second electrode layer is electrically connected to a second conductive path extending from the inside of the case to the outside via a conductive plate. The conductive plate includes a flat portion facing the power generation element and a spring portion that rises from the flat portion to press the power generation element toward the bottom of the concave container, and is concave radially outward from the power generation element when viewed in plan. It is fastened to the side wall of the mold container. A gap is formed between the conductive plate and the cover material.

In this way, the conductive plate is locked and fixed to the side wall of the concave container radially outward from the power generation element when viewed in plan, and the spring portion of the conductive plate presses the power generation element toward the bottom of the concave container. , the conductive plate can conduct the power generation element more stably than the first conduction path and the second conduction path without causing positional misalignment in the conductive plate due to vibration or the like. Thereby, the electrochemical element can maintain good electrical connection. Additionally, since the cover material does not come into contact with the conductive plate, the cover material is not affected by pressure on the conductive plate during sealing, and the sealability of the case can be improved.

(Configuration 2)

In the electrochemical element of Configuration 1, the spring portion may be cantilevered on the flat portion and may have a spring piece that presses the power generation element toward the bottom of the concave container. As a result, since the spring piece only needs to be formed on a part of the flat portion of the conductive plate, the manufacture of the conductive plate, that is, the manufacture of the electrochemical element, can be easily performed.

(Configuration 3)

In the electrochemical element of Configuration 1, the conductive plate may have a plurality of spring portions that rise from the flat portion and press the power generation element toward the bottom of the concave container. As a result, the number of conductive points between the conductive plate and the power generation element increases, so that electrical resistance can be reduced and electrical connection can be made more reliably. Additionally, by dispersing the pressurized points of the power generation elements, the overall pressurizing force can be increased.

(Configuration 4)

In the electrochemical element of Configuration 3, each of the plurality of spring parts may be cantilevered on the flat surface and may also have a spring piece that presses the power generation element toward the bottom of the concave container. As a result, since the spring pieces need only be formed at a plurality of locations on the flat portion of the conductive plate, the manufacture of the conductive plate, that is, the manufacture of the electrochemical element, can be easily performed.

(Configuration 5)

In the electrochemical element of Configuration 4, each of the plurality of spring pieces may be arranged so as to be line symmetrical or point symmetrical when viewed from the top. That is, the plurality of spring pieces may be arranged so as to have at least one of line symmetry and point symmetry when viewed from the top. Thereby, since the contact points of the tip of the spring piece and the power generation element are arranged in contrast, the pressing force of the spring piece to the power generation element can be evenly distributed.

(Configuration 6)

In the electrochemical element of configuration 4, the spring pieces in the plurality of spring parts may be arranged radially when viewed from the top. As a result, since the contact points of the tip of the spring piece and the power generation element are arranged in contrast, the pressing force of the spring piece to the power generation element can be evenly distributed.

(Configuration 7)

In the electrochemical device of configuration 2, the spring piece may be formed so that the width of the spring piece cantilevered and supported on the flat portion is wider than the width of the tip portion. Thereby, stress concentration at the cantilever-supported location can be alleviated and damage to the spring piece can be suppressed. In addition, by making the width of the tip of the spring piece in contact with the second electrode layer narrower than the width of the cantilevered support on the flat surface, the tip of the spring piece becomes prone to bending, causing variations in the thickness of the power generation element and the side wall of the concave container. Deviations in height, etc. can be easily absorbed.

(Configuration 8)

In the electrochemical element of Configuration 2, the spring piece may be formed so that the width of the tip portion is wider than the width of the cantilevered support on the flat portion. As a result, the electrical connection point between the spring piece and the power generation element is expanded, so that electrical resistance can be reduced.

(Configuration 9)

In the electrochemical device of Configuration 2, the spring piece may be a disc spring. Thereby, even if the thickness of the spring piece is reduced, the pressing force of the spring piece to the power generation element can be improved.

(Configuration 10)

In any of the electrochemical elements of configurations 2, 4 to 9, the tip of the spring piece may be bent in a direction opposite to the power generation element. Thereby, it is possible to prevent the sharp point of the tip of the spring piece from coming into contact with the power generation element and causing injury.

(Configuration 11)

In any of the electrochemical elements of Configurations 1 to 10, the power generation element may further have a porous metal layer on the surface of the second electrode layer. As a result, the porous metal layer pressed from the conductive plate is compressed by a certain amount and can sufficiently absorb variations in the thickness of the power generation element or the height of the case, etc. As a result, variation in the value of internal resistance can be suppressed. Alternatively, if the porous metal layer is integrated with the second electrode layer in advance, the electrical resistance at the conduction point between the spring portion and the power generation element can be reduced.

(Configuration 12)

An electrochemical element related to another embodiment of the present disclosure includes a case having a concave container having a bottom portion and a side wall portion and a cover material that covers the opening of the concave container, and a first material sealed in the case and disposed on the bottom side. An exterior material including an electrode terminal and a second electrode terminal disposed on the side of the cover material, and an insulating layer encapsulated inside the exterior material and disposed between the first electrode layer, the second electrode layer, and the first electrode layer and the second electrode layer. It is provided with a flat element having a power generation element and a conductive plate disposed between the flat element and the cover material. The first electrode terminal is electrically connected to a first conductive path extending from the inside of the case to the outside. The second electrode terminal is electrically connected to a second conductive path extending from the inside of the case to the outside via a conductive plate. The conductive plate includes a flat portion facing the flat element and a spring portion that rises from the flat portion to press the flat element toward the bottom of the concave container, and is concave radially outward from the flat element when viewed from the top. It is fastened to the side wall of the mold container. A gap is formed between the conductive plate and the cover material. As a result, the electrochemical element can maintain good electrical connection without displacement of the conductive plate due to vibration or the like. Additionally, since the cover material does not contact the conductive plate, the cover material is not affected by pressure from the conductive plate during sealing, and the sealability of the case can be improved.

(Composition 13)

In the electrochemical element of Configuration 13, the spring portion may have a spring piece that is cantilevered on the flat portion and presses the flat element toward the bottom of the concave container. As a result, since the spring piece only needs to be formed on a part of the flat portion of the conductive plate, the manufacture of the conductive plate, that is, the manufacture of the electrochemical element, can be easily performed.

(First Embodiment)

Hereinafter, the first embodiment of the present disclosure will be described in detail using FIGS. 1 to 16, taking the case where the electrochemical element is an all-solid-state battery as an example. First, as shown in FIG. 1, the electrochemical element 1 includes a case 10, a power generation element 20 and a conductive plate 30 accommodated in the case 10, and an external surface of the case 10. It consists of an external terminal 13 and an external terminal 14 arranged in .

Case 10 has a concave container 11 and a cover material 12. The concave container 11 is made of ceramics. The concave container 11 is formed continuously from the outer periphery of the bottom 111 and the square-shaped bottom 111, and is a quadrangular container having a cylindrical space for accommodating the power generation element 20 therein. It includes a shaped side wall portion 112. The side wall portion 112 is provided to extend substantially perpendicular to the bottom portion 111 when viewed in longitudinal section. A conductor portion 113 is formed inside the bottom portion 111. The conductor portion 113 is provided to extend between the power generation element 20 and the bottom portion 111 so as to be conductively connected to the power generation element 20, and forms a conduction path corresponding to the electrode layer 21. Inside the side wall portion 112, a conductor portion 114 is formed. As shown in FIG. 1, a part of the conductor portion 114 is formed on the inner peripheral surface of the side wall portion 112, exposed to the lower surface and side surface of the support portion 115 to be described later, and corresponds to the electrode layer 22. A conduction path is formed. The manufacturing method of the concave container 11 will be described later. In addition, the material of the concave container 11 is not particularly limited, and various examples include resin, glass (borosilicate glass, glass ceramics, etc.), metal, and ceramic. It may be a composite material in which ceramic or glass powder is dispersed in a resin. When the concave container 11 is made of a metal material, the concave container 11 and the power generation element 20 are insulated, or the concave container 11 and the flat element 50 described later (see FIG. 19) are used. In order to ensure insulation, it is desirable to cover the inner surface of the bottom part 111 and the inner peripheral surface of the side wall part 112 of the concave container 11 with an insulating material such as a resin material or glass. In addition, the concave container 11 is not limited to a square shape in plan view, and may have a circular shape, an elliptical shape, a polygonal shape, etc. The internal space for accommodating the power generation element 20 is not limited to a cylindrical shape, and may be formed in a polygonal cylindrical shape such as a quadrangular cylindrical shape depending on the shape of the power generation element 20. In addition, the conductor portion 114 is formed not on the inside of the side wall portion 112, but on the inner surface of the side wall portion 112, and further penetrates the inside of the bottom portion 111 to be connected to the external terminal 14. do. In this case, between the outer peripheral surface of the power generation element 20 and the conductor portion 114, for example, on the inner surface of the conductor portion 114, to prevent the outer peripheral surface of the power generation element 20 from contacting the conductor portion 114. It is desirable to form an insulating layer.

The side wall portion 112 has a plurality of support portions 115 that support the conductive plate 30 described later. In this embodiment, the support portion 115 is formed at the upper end of the inner peripheral surface of the side wall portion 112 and is a protrusion that protrudes along the circumferential direction of the inner peripheral surface. More specifically, as shown in FIG. 2, the support portion 115 is a plurality of concave ceilings formed radially outward on the inner peripheral surface of the side wall portion 112. As a result, the support portion 115 is formed to protrude in the circumferential direction of the inner peripheral surface. The lower surface of each support portion 115, that is, the lower surface of each ceiling wall, is radially outward from the power generation element 20 when viewed in plan, and holds the supported portion 31 of the conductive plate 30 to be described later. You can support it. Additionally, in this embodiment, four support portions 115 are provided, but the number is not limited. For example, in the case where the supported portions 31 of the conductive plate 30 are two, the supported portions 31 Two supports 115 may be provided at positions corresponding to .

The cover material 12 is a rectangular thin metal plate that covers the opening of the concave container 11. As shown in FIGS. 1 and 3, the cover material 12 is a concave container by means of a seal ring 15 in the shape of a square frame disposed between the lower surface of its outer peripheral end and the upper end of the concave container 11. It is joined (seam welded) at (11). As a result, the internal space of case 10 is completely sealed. The internal space of the case 10 is preferably in a vacuum atmosphere or an inert gas atmosphere such as nitrogen, considering the influence on the power generation element 20. In addition, the cover material 12 is not limited to a thin metal plate as long as it can cover the opening of the concave container 11. The cover material 12 is not limited to a square shape, and can be variously changed into a circular shape, an elliptical shape, a polygonal shape, etc., depending on the shape of the concave container 11 when viewed from the top. Additionally, the cover material 12 may have a shape other than a flat plate. In addition, the cover material 12 may be bonded to the concave container 11 by an adhesive, and the method of joining the cover material 12 and the concave container 11 can be used as long as the internal space of the case 10 can be sealed. is not particularly limited.

The external terminal 13 is disposed on the outer surface of the bottom 111 of the concave container 11. The external terminal 13 is electrically connected to the electrode layer 21 described later via the conductor portion 113. The electrode layer 21 functions as a positive electrode layer as will be described later. Therefore, the conductor portion 113 serves as a conductive path that connects the external terminal 13 and the positive electrode layer, and the external terminal 13 functions as a positive electrode terminal.

The external terminal 14 is arranged on the outer surface of the bottom 111 of the concave container 11 away from the external terminal 13. The external terminal 14 is electrically connected to the supported portion 31 of the conductive plate 30, which will be described later, via the conductor portion 114. As will be described later, the conductive plate 30 is electrically connected to the electrode layer 22 that functions as a negative electrode layer. Therefore, the conductor portion 114 serves as a conductive path that connects the external terminal 14 and the negative electrode layer, and the conductive plate 30 serves as a connection terminal that connects this conductive path with the electrode layer 22. The terminal 14 functions as a negative terminal. In addition, the arrangement of the external terminal 13 and the external terminal 14 is not limited to the above, and may be arranged on the outer surface of the side wall portion 112 of the concave container 11, and the cover material 12 may be connected to the conductor portion. It is also possible to form the external terminal 14 on the outer surface of the cover material 12 by functioning as 114. However, by arranging these two terminals at regular intervals on the outer surface of the bottom 111 of the concave container 11, mounting on the surface of the circuit board becomes easy.

Here, the manufacturing method of the concave container 11 will be described. First, metal paste is printed and applied to a ceramic green sheet to form printed patterns that become the conductor portions 113 and 114. Next, a plurality of green sheets forming these print patterns are stacked and fired. By stacking a plurality of green sheets of different shapes, the above-described support portion 115 is formed. As a result, the concave container 11 having the conductor portion 113 and 114 inside and the support portion 115 described above on the inner peripheral surface of the side wall portion 112 can be manufactured. Additionally, as long as the support portion 115 can be formed on the inner peripheral surface of the side wall portion 112, this manufacturing method is not limited. In addition, the external terminal 13 and the external terminal 14 can also be formed by a printed pattern of this metal paste.

The power generation element 20 includes a laminate in which an electrode layer (positive electrode layer) 21, an electrode layer (negative electrode layer) 22, and a solid electrolyte layer 23 are laminated. The solid electrolyte layer 23 is disposed between the electrode layer 21 and the electrode layer 22 as an isolation layer. That is, in this embodiment, the isolation layer is the solid electrolyte layer 23. The power generation element 20 is formed in a cylindrical shape. The power generation element 20 is stacked in the order of the electrode layer 21, the solid electrolyte layer 23, and the electrode layer 22 from the bottom 111 side (downward in the drawing) of the concave container 11. That is, the power generation element 20 is arranged so that one end of the electrode layer 21 is on the bottom 111 side of the concave container 11, and the other end of the electrode layer 22 is a cover. It is arranged so as to be on the material 12 side and is accommodated in the internal space of the case 10. Additionally, the power generation element 20 is not limited to a cylindrical shape, and can be changed to various shapes such as a rectangular parallelepiped shape or a polygonal column shape. Additionally, the power generation element 20 may have a plurality of laminates. A plurality of laminates may be stacked so as to be connected in series.

The electrode layer 21 is a positive electrode pellet formed by forming a positive electrode mixture into a cylindrical shape containing lithium cobaltate as a positive electrode active material, a sulfide-based solid electrolyte, and graphene as a conductive additive in a mass ratio of 65:30:5. . In addition, the positive electrode active material of the electrode layer 21 is not particularly limited as long as it can function as a positive electrode layer of the power generation element 20, and examples include lithium nickelate, lithium manganate, and lithium nickel cobalt manganese composite oxide. , olivine-type complex oxide, etc., or an appropriate mixture thereof may be used. There is no particular limitation on other constituent materials or ratios. Additionally, the size and shape of the electrode layer 21 are not limited to a cylindrical shape and can be changed in various ways depending on the size and shape of the electrochemical element 1.

The electrode layer 22 is a negative electrode active material used in lithium ion secondary batteries, and is composed of LTO (Li ₄ Ti ₅ O ₁₂ , lithium titanate), a sulfide-based solid electrolyte, and graphene in a weight ratio of 50:40:10. It is a negative electrode pellet formed by molding the negative electrode mixture it contains into a cylindrical shape. In addition, the negative electrode active material of the electrode layer 22 is not particularly limited as long as it can function as the negative electrode layer of the power generation element 20, and for example, metal lithium, lithium alloy, graphite, low crystalline material, etc. It may be a carbon material such as carbon, an oxide such as SiO, or an appropriate mixture of these. There is no particular limitation on other constituent materials or ratios. Additionally, the size and shape of the electrode layer 22 are not limited to a cylindrical shape and can be changed in various ways depending on the size and shape of the electrochemical element 1.

The solid electrolyte layer (isolation layer) 23 contains a sulfide-based solid electrolyte. The solid electrolyte layer 23 is formed into a cylindrical shape. In addition, the solid electrolyte contained in the electrode layer 21, the electrode layer 22, and the solid electrolyte layer 23 is not particularly limited, but is a sulfide-based solid electrolyte in terms of ion conductivity, especially an azyrodite-type sulfide-based solid. An electrolyte is preferably used. When using a sulfide-based solid electrolyte, it is preferable to cover the surface of the positive electrode active material with a lithium ion conductive material such as niobium oxide to prevent reaction with the positive electrode active material. In addition, the solid electrolyte contained in the solid electrolyte layer 23, the electrode layer 21, and the electrode layer 22 may be a hydride-based solid electrolyte, an oxide-based solid electrolyte, or the like. Additionally, the size and shape of the solid electrolyte layer 23 are not limited to a cylindrical shape and can be changed in various ways depending on the size and shape of the electrochemical element 1.

As shown in FIGS. 1 and 4 , the conductive plate 30 is a metal plate installed in the opening of the concave container 11 of the case 10 and has a square shape in plan view. The conductive plate 30 has a plurality of supported portions 31 corresponding to the positions of each of the above-described supporting portions 115 radially outward from the power generation element 20 when viewed in plan. In this embodiment, the supported portion 31 is the above-described support portion 115, that is, a hook-shaped fastening piece fastened to the lower surface of the fabric wall. More specifically, the supported portion 31 extends from the edge of the conductive plate 30 toward the support portion 115 described above (downward in FIG. 1). The supported portion 31 has a supporting portion 115, that is, a tip that is bent back toward the lower surface of the fabric wall. The tip of the supported portion 31 is in contact with the conductor portion 114 exposed on the lower surface and side surface of the ceiling wall described above. As a result, the conductive plate 30 not only functions as a current collector but also functions as a connection terminal that electrically connects the conductive path connected to the electrode layer 22 and the external terminal 14. The conductive plate 30 is supported on the support portion 115 formed on the inner peripheral surface of the concave container 11 and covers a part of the opening of the concave container 11. The area of the conductive plate 30 when viewed from the top is smaller than the opening area of the concave container 11. In addition, even if the hook-shaped locking piece is not fastened to the lower surface of the fabric wall, if the conductive plate 30 can be fixed in a state in which the hook-shaped locking piece is press-fitted into the concave portion formed on the inner peripheral surface of the side wall portion 112, the conductive plate 30 ) is assumed to be locked to the side wall portion 112 of the concave container 11.

As shown in FIG. 1, the conductive plate 30 is extended from the flat portion 32 of the conductive plate 30 so as to contact the upper surface of the electrode layer 22, which is the other end of the power generation element 20. It has a spring portion 33 rising toward the electrode layer 22 of 20). The shape of the spring portion 33 is not particularly limited as long as it can press the power generation element 20 in the direction of the bottom portion 111 of the concave container 11. In this embodiment, the spring portion 33 is a spring piece inclined from the flat portion 32 toward the electrode layer 22 of the power generation element 20 (hereinafter, the spring portion 33 is referred to as the spring piece 33). There are cases where it is called.). As shown in Fig. 4, the spring piece 33 is formed by cutting out a portion of the flat portion 32 in a U-shape, and is cantilevered and supported on the flat portion 32. That is, in this embodiment, the spring piece 33 is a leaf spring. In this way, since the spring piece 33 can be formed on a part of the flat portion 32, the manufacture of the conductive plate, that is, the manufacture of the electrochemical element, can be easily performed. Additionally, by cutting out the flat portion 32 to form the spring piece 33, the manufacture of the conductive plate, that is, the manufacture of the electrochemical element, can be performed more easily. The spring piece 33 has a boundary 331 with the flat portion 32 and a tip portion 332 that is brought into contact with the electrode layer 22 of the power generation element 20 and brought into conduction with the electrode layer 22 . The spring piece 33 is bent at the boundary 331 and is inclined toward the power generation element 20 from the boundary 331 toward the distal end 332. The height from the bottom surface of the flat portion 32 before assembling the electrochemical element 1 to the tip portion 332 (height of the spring portion 33) is the flat portion after assembling the electrochemical element 1 ( It is greater than the height from the bottom surface of 32) to the power generation element 20. As a result, the power generation element 20 can be pressed by the tip 332 of the spring piece 33, and good electrical connection between the conductive plate 30 and the power generation element 20 can be maintained. Additionally, by constructing the spring portion 33 from a spring piece, the thickness of the conductive plate 30 excluding the supported portion 31 can be reduced. For example, before assembling the electrochemical element 1, the thickness of the conductive plate 30 excluding the supported portion 31 is the thickness of the plate forming the flat portion 32 and the spring piece 33. It can be said to be the sum of the heights of . Specifically, the thickness of the plate material: 0.2 mm and the height of the spring piece 33: 0.5 mm can be combined to make the thickness of the conductive plate 30 excluding the supported portion 31 0.7 mm. Additionally, the width of the spring piece 33 can be 1.5 mm, the length can be 3 mm, etc. In addition, when providing a plurality of spring pieces 33, the shapes including the width and length of the spring pieces 33 may be individually different for reasons such as preventing resonance. The thickness of the conductive plate 30 excluding the supported portion 31 is preferably 1.2 mm or less, more preferably 1 mm or less, and especially preferably 0.8 mm or less. Meanwhile, in order to generate the necessary pressing force on the spring portion 33, the thickness of the conductive plate 30 excluding the supported portion 31 is preferably 0.3 mm or more, and more preferably 0.4 mm or more, It is particularly preferable to set it to 0.5 mm or more.

Additionally, since the position of the edge of the conductive plate 30, that is, the supported portion 31, can be freely set in the height direction (thickness direction of the conductive plate 30), the cover material 12 and the conductive plate Even when a gap is formed between (30), the distance between the cover material (12) and the tip portion (332) of the spring piece (33) does not increase. As a result, expansion of the gap between the cover material 12 and the power generation element 20 can be suppressed, making it possible to achieve higher capacity of the electrochemical element 1. Here, the overall thickness of the conductive plate 30 including the supported portion 31 can be appropriately adjusted depending on the height from the bottom portion 111 of the side wall portion 112 of the concave container 11. there is. The supported portion 31 just needs to have the height required for locking to the supporting portion 115. Therefore, the overall thickness of the conductive plate 30 including the supported portion 31 can be, for example, 3 mm or less, preferably 2.7 mm or less, and more preferably 2.5 mm or less. In addition, the thickness direction is the vertical direction (height direction of the electrochemical element 1) in FIG. 1, and can also be said to be a direction perpendicular to the bottom surface of the flat portion 32 in the illustration. Additionally, the spring piece 33 may be formed by cutting out the flat portion 32 as described above, and similarly in the modified example described later, the spring piece 33 may be formed separately on the bottom surface of the flat portion 32. The spring piece 33 may be mounted by welding or otherwise. Additionally, separately from the flat portion 32, a base for mounting the spring piece 33 may be prepared in advance, and the spring piece 33 may be mounted on the base to make the entire spring portion. That is, the spring piece 33 may rise directly from the flat portion 32, or may rise from the flat portion 32 through another element such as a base. Additionally, both ends of the spring piece 33 may be supported on the flat portion 32 so that the spring piece 33 has a convex shape toward the power generation element 20.

Examples of metals constituting the conductive plate 30 include nickel, iron, copper, chromium, cobalt, titanium, aluminum, and alloys thereof. In order to facilitate the function as a leaf spring, SUS301-CSP, SUS304- Stainless steels for springs such as CSP, SUS316-CSP, SUS420J2-CSP, SUS631-CSP, and SUS632J1-CSP are preferably used.

In addition, the thickness of the conductive plate 30 is preferably 0.05 mm or more, more preferably 0.07 mm or more, and 0.1 mm or more in order to keep the pressing force on the power generation element 20 above a certain level. It is especially desirable to do so. Meanwhile, to prevent the conductive plate 30 from becoming too thick and thus increasing the storage volume in the case 10, and to make the conductive plate 30 easily deformable so that it can be easily fastened to the side wall portion 112. For this purpose, the thickness of the conductive plate 30 is preferably 0.5 mm or less, more preferably 0.4 mm or less, and especially preferably 0.3 mm or less.

The conductive plate 30 is placed on the upper surface of the power generation element 20 after the power generation element 20 is accommodated inside the concave container 11. In a state where the conductive plate 30 is placed on the upper surface of the power generation element 20, the tip of the supported portion 31 is positioned in the axial direction of the power generation element 20 (up and down direction in FIG. 1). ) can be positioned between the upper surface of the support portion 115, that is, the lower surface of the ceiling wall. Then, while pushing the supported portion 31 of the conductive plate 30 toward the bottom 111 of the concave container 11, the supported portion 31 is supported on the supporting portion 115. More specifically, the tip of the supported portion 31 is fastened to the supporting portion 115, that is, the lower surface of the fabric wall. Since the supported portion 31 is pushed downward, the spring piece 33 of the conductive plate 30 is pushed in the opposite direction to the electrode layer 22 while in contact with the power generation element 20. The spring piece 33 presses the power generation element 20 in the direction of the bottom 111 of the concave container 11 by its elastic force. As a result, the conductive plate 30 can more stably contact the power generation element 20 and maintain good electrical connection without displacement due to vibration or the like. The spring piece 33 is not particularly limited as long as it can press the power generation element 20 toward the bottom 111 of the concave container 11 by its elastic force. Additionally, the concave container 11 has two support parts 115, but the number of support parts 115 may be two or more. The supported portion 31 may be formed according to the number of supporting portions 115. In addition, as a method of fixing the edge end (supported portion 31) of the conductive plate 30 to the inner peripheral surface of the side wall portion 112 of the concave container 11, the side wall portion 112 of the concave container 11 A method of adhering the edge of the conductive plate 30 to the inner peripheral surface is also exemplified.

A gap is formed between the conductive plate 30 and the cover material 12. That is, the conductive plate 30 and the cover material 12 do not contact each other. As a result, even when the conductive plate 30 is pushed toward the cover material 12 due to a change in the volume of the power generation element 20, deformation of the cover material 12 can be suppressed. Additionally, the cover material 12 and the concave container 11 are welded via the seal ring 15 as described above. By providing a gap between the conductive plate 30 and the cover material 12, the influence of welding heat on the power generation element 20 can be suppressed. Additionally, since the conductive plate 30 and the cover material 12 are not in contact, when the cover material 12 is joined to the upper surface of the side wall portion 112 of the concave container 11, the conductive plate 30 It is not affected by pressure from, and the sealability of the case 10 can be further improved.

Here, modification examples 1 to 10 of the conductive plate 30 will be described. In addition, here, the description of the same configuration as the above-described conductive plate 30 will be omitted, and only the configuration that is fundamentally different from the above-described conductive plate 30 will be described.

(Variation Example 1)

5 and 6, the conductive plate 30 of Modification Example 1 has two spring pieces 33. As shown in Fig. 6, the two spring pieces 33 are arranged so as to be linearly symmetrical when viewed from the top. More specifically, the two spring pieces 33 are formed to be linearly symmetrical with respect to a predetermined virtual axis A on the flat portion 32. That is, the two spring pieces 33 are each inclined from the flat portion 32 toward the virtual axis A toward the electrode layer 22 of the power generation element 20, as shown in the inclined direction D in the drawing. . Accordingly, the tip portions 332 of the two spring pieces 33 face each other via the virtual axis A. In other words, the two spring pieces 33 are formed so that they face each other and can be bent. These two spring pieces 33 may be arranged in plural numbers in the direction along the virtual axis A. For example, when the two spring pieces 33 of Modification 1 are arranged in 5 rows in the direction along the virtual axis A, 10 spring pieces 33 are formed. In this way, by providing a plurality of spring pieces 33 so as to be linearly symmetrical with respect to the predetermined virtual axis A, the contact area between the tip portion 332 of the spring piece 33 and the electrode layer 22 increases, so that the electrical power Resistance can be reduced. In addition, since the contact points between the distal end 332 of the spring piece 33 and the electrode layer 22 are symmetrically disposed, the pressing force of the spring piece 33 to the electrode layer 22 is evenly distributed, and the overall The pressing force can be increased. Additionally, the position of the virtual axis A can be determined arbitrarily as long as a plurality of spring pieces 33 can be formed and the power generation element 20 can be appropriately pressed.

(Variation 2)

As shown in Fig. 7, the conductive plate 30 of Modification Example 2 has two spring pieces 33. The two spring pieces 33 are arranged so as to be point symmetrical when viewed from the top. More specifically, the two spring pieces 33 are formed to be point symmetrical with respect to the virtual point C on the flat portion 32. As indicated by the inclination direction D in the drawing, the two spring pieces 33 each have a parallel inclination direction, and one spring piece 33 has a direction opposite to that of the other spring piece 33. It is arranged to have an inclination direction (D) of. The conductive plate 30 of Modification 2 may have a plurality of spring pieces 33, two or three or more. In this case, the inclination direction D of the spring pieces 33 is parallel, and a plurality of spring pieces 33 are arranged in parallel so that the inclination directions of adjacent spring pieces 33 are alternate. The length of each of the plurality of spring pieces 33 in the inclined direction D is the same. As a result, the number of contact points between the distal end 332 of the spring piece 33 and the electrode layer 22 increases, and a plurality of spring pieces 33 are arranged in an alternating inclination direction between adjacent spring pieces 33. , electrical resistance can be reduced. In addition, since the contact points between the distal end 332 of the spring piece 33 and the electrode layer 22 are symmetrically disposed, the pressing force of the spring piece 33 to the electrode layer 22 is evenly distributed, and the overall The pressing force can be increased. Additionally, the position of the virtual point C can be determined arbitrarily as long as a plurality of spring pieces 33 can be formed on the flat portion 32 and the power generation element 20 can be appropriately pressed. However, the virtual point C is preferably set at a position corresponding to the geometric center of the power generation element 20 on the plane portion 32.

(Variation 3)

As shown in Fig. 8, the conductive plate 30 of Modification Example 3 has four spring pieces 33. The four spring pieces 33 are formed by cutting out the flat portion 32 in a cross shape. Each spring piece 33 is arranged on a virtual radiation extending from the center point P. The inclination directions D of the four spring pieces 33 each face the center point P. That is, among the four spring pieces 33, the lines connecting the inclination directions D of the two opposing spring pieces 33 intersect. The four spring pieces 33 are arranged on the virtual radiation so that each spring piece 33 is equiangular with respect to the center point P. In this modification 3, the angle θ with respect to the center point P of the adjacent spring piece 33 is 90°C. The boundary 331 of each spring piece 33 can be a tangent to a circle centered on the center point P. Additionally, the length of each spring piece 33 in the inclined direction D may be the same. The conductive plate 30 of Modification 3 is not limited to having four spring pieces 33, and may have a plurality of spring pieces 33 of two, three, or five or more. Thereby, the electrical resistance can be reduced, and in addition, the pressing force of the spring piece 33 to the electrode layer 22 can be distributed evenly, and the overall pressing force can be increased.

(Variation Example 4)

As shown in FIG. 9 , the conductive plate 30 of Modification Example 4 has a spring piece 33 whose tip portion 332 is bent in a direction opposite to that of the electrode layer 22 . That is, the tip portion 332 is formed in a convex shape toward the electrode layer 22. The tip portion 332 preferably has a convex curved surface toward the electrode layer 22. Additionally, the tip portion 332 may be bent in multiple ways so that the tip portion 332 and the electrode layer 22 are brought into surface contact. For example, by bending the tip 322 twice, a contact surface with the electrode layer 22 can be formed on the tip 332. As a result, it is possible to prevent a sharp point of the tip portion 332 from coming into contact with the electrode layer 22 and causing injury. Additionally, the tip portion 332 of the spring piece 33 of another modified example may be similarly bent.

(Variation 5)

As shown in Fig. 10, the conductive plate 30 of Modification Example 5 has spring pieces 33 in a trapezoidal shape. The width L1 of the boundary 331 is wider than the width L2 of the tip portion 332. The width L1 of the border 331 may be expressed as the width of the bent portion of the spring piece 33 bent with respect to the flat portion 32, or the width cantilevered and supported on the flat portion 32. . The width L1 of the tip portion 332 may be said to be the width of the portion in contact with the electrode layer 22 of the power generation element 20 (i.e., the portion that conducts with the electrode layer 22). In addition, of the opposite sides of the trapezoidal spring piece 33, the relatively long side may be referred to as the border 331, and the relatively short side may be referred to as the distal end 332. As a result, when the spring piece 33 contacts the electrode layer 22, the relatively narrow tip portion 332 is likely to bend in the direction opposite to the electrode layer 22, causing a deviation in the thickness of the power generation element 20 or It is possible to easily absorb variations in the height of the side wall portion 112 of the concave container 11. In addition, by forming the boundary 331, which is the bending point, relatively long, the stress concentration at the boundary 331 is alleviated, and the spring piece 33 is separated from the flat portion 32, etc., so that the conductive plate 30 Damage can be prevented.

(Variation 6)

As shown in Fig. 11, the conductive plate 30 of Modification Example 6 has spring pieces 33 in an inverted trapezoid shape. The width L2 of the tip 332 is wider than the width L1 of the border 331. As a result, the contact point between the distal end 332 of the spring piece 33 and the electrode layer 22 increases, so that the electrical resistance can be reduced and the pressing force of the spring piece 33 to the electrode layer 22 can be increased. You can. In addition, in the spring pieces 33 of Modification Example 5 and Modification 6 described above, when the tip portion 332 is bent like the spring piece 33 of Modification Example 4, or contact with the electrode layer 22 When the tip 332 is bent, the spring piece 33 contacts the electrode layer 22 on the border 331 side rather than the tip. In this case, the width of the location where the spring piece 33 contacts the electrode layer 22, that is, the location where the spring piece 33 and the electrode layer 22 conduct, is regarded as the width L2 of the tip portion 332. Let's do it.

(Variation 7)

As shown in Fig. 12, the conductive plate 30 of Modification Example 7 is cut out in the vicinity of the boundary 331 in a curved shape when viewed from the top. That is, the width L1 of the border 331 is wider than the width L2 of the tip portion 332. Thereby, the same effect as the spring piece 33 of Modification Example 5 can be achieved.

(Variation 8)

As shown in Fig. 13, the conductive plate 30 of Modification Example 8 has a triangular spring piece 33. The border 331 is a predetermined side of the triangular spring piece 33, and the tip 332 is the vertex of the triangular spring piece 33. That is, the triangular spring piece 33 has a narrow front from the boundary 331 toward the distal end 332. Here, the tip portion 332 is the vertex, but actually has a predetermined width L2 (not shown) in contact with the electrode layer 22. Therefore, also in the spring piece 33 of Modification 8, it can be said that the width L1 of the border 331 is wider than the width L2 of the distal end 332. Thereby, the same effect as the spring piece 33 of Modification Example 5 can be achieved.

(Variation 9)

As shown in Fig. 14, the conductive plate 30 of Modification Example 9 has a spring piece 33 having a semi-elliptical shape. The semi-elliptical spring piece 33 is formed by cutting out the flat portion 32 into a U shape. The semi-elliptical spring piece 33 has a narrow front from the border 331 toward the distal end 332. Here, the distal end 332 has a curved shape when viewed from the top, but actually has a predetermined width L2 (not shown) in contact with the electrode layer 22. Therefore, also in the spring piece 33 of Modification Example 9, it can be said that the width L1 of the border 331 is wider than the width L2 of the distal end 332. Thereby, the same effect as the spring piece 33 of Modification Example 5 can be achieved.

(Variation 10)

As shown in Figs. 15 and 16, the spring piece 33 of Modification 10 is a disc spring and is a peripheral wall of a truncated cone whose diameter gradually decreases from the flat portion 32 toward the power generation element 20. That is, the diameter of the border 331 is larger than the diameter of the tip 332, and the length of the border 331 is longer than the length of the tip 332. Thereby, the same effect as the spring piece 33 of Modification Example 5 can be achieved.

The spring piece 33 of the first embodiment and the spring pieces 33 of its modification examples 1 to 10 may be provided in various combinations with respect to the conductive plate 30.

(Second Embodiment)

Next, the electrochemical element 1 of the second embodiment will be described in detail using FIG. 17. In the electrochemical element 1 of the present embodiment, the description is basically omitted for the same configuration as the electrochemical element 1 of the first embodiment, and the electrochemical element 1 of the first embodiment is different from that of the electrochemical element 1 of the first embodiment. Only the configuration is explained.

In the electrochemical element 1 of this embodiment, the power generation element 20 has a porous metal layer 24. The porous metal layer 24 is disposed on the surface of the electrode layer 22, and connects the electrode layer 22 and the conductive plate 30 by contacting the distal end 332 of the spring piece 33.

The porous metal layer 24 is a porous metal base having a high porosity and pores penetrating from one side to the other side, like a foamed metal porous body, and can be compressed by pressurization. It functions as a whole. The porous metal layer 24 covers the surface of the electrode layer 22. In order to reduce the electrical resistance, the porous metal layer 24 is not only in contact with the electrode layer 22, but also is integrated with the electrode layer 22 by partially embedding it in the negative electrode mixture of the electrode layer 22. desirable. Additionally, as shown in FIG. 17, a porous metal layer 24 may be disposed on the surface of the electrode layer 21 on the lower surface of the electrode layer 22, that is, on the bottom portion 111 side, and a portion of the porous metal layer 24 may be formed on the electrode layer ( The porous metal layer 24 may be provided so as to be embedded in the positive electrode mixture of 21) and integrated with the electrode layer 21.

The porosity of the porous metal layer 24 is preferably 80% or more, and more preferably 90% or more, in order to easily adjust the variation in the thickness of the power generation element 20 due to compression. Meanwhile, in order to ensure good conductivity, the porosity of the porous metal layer 24 is preferably 99% or less. The thickness of the porous metal layer 24 before assembling the electrochemical element 1 is preferably 0.1 mm or more, more preferably 0.3 mm or more, particularly preferably 0.5 mm or more, and preferably 3 mm or less. , it is more preferable that it is 2 mm or less, and it is especially preferable that it is 1.5 mm or less.

By providing the porous metal layer 24 in this way, it is possible to sufficiently absorb variation in the thickness of the power generation element 20 or the height of the case 10, and as a result, variation in the value of internal resistance can be suppressed. there is. Alternatively, if the porous metal layer 24 is integrated with the second electrode layer in advance, the electrical resistance at the conduction point between the spring portion 33 and the power generation element 20 can be reduced.

(Third Embodiment)

Next, the electrochemical element 1 of the second embodiment will be described in detail using FIG. 18. In the electrochemical element 1 of the present embodiment, the description is basically omitted for the same configuration as the electrochemical element 1 of the first embodiment, and the electrochemical element 1 of the first embodiment is different from that of the electrochemical element 1 of the first embodiment. Only the configuration is explained.

The electrochemical element 1 of this embodiment has a conductive sheet 40 between the electrode layer 22 and the conductive plate 30. In this embodiment, the conductive sheet 40 is a conductive carbon sheet made of expanded graphite, that is, a graphite sheet. The graphite sheet is manufactured as follows. First, particles of acid-treated graphite, which is acid-treated natural graphite, are heated. In that case, the acid-treated graphite expands as the acid between its layers vaporizes and foams. This expanded graphite (expanded graphite) is molded into a felt shape and further rolled using a roll mill to form a sheet body. The conductive sheet 40 is manufactured by cutting out this sheet of expanded graphite into a circular shape. As described above, expanded graphite is formed when acid vaporizes and acid-treated graphite foams. Therefore, the graphite sheet is formed in a porous shape. Therefore, the graphite sheet has the conductivity of the graphite itself, as well as flexibility that is not present in conventional graphite products. In addition, the method of manufacturing the graphite sheet is not limited to this, and the graphite sheet may be made of a material other than expanded graphite, and the graphite sheet may be manufactured by any method.

The apparent density of the graphite sheet is preferably 0.3 g/cm 3 or more, more preferably 0.7 g/cm 3 or more, preferably 1.5 g/cm 3 or less, and more preferably 1.3 g/cm 3 or less. If the apparent density of the graphite sheet is too low, the graphite sheet becomes easily damaged, and if the apparent density is too high, flexibility decreases. In addition, the apparent density is not limited to the graphite sheet, and can also be applied to the conductive sheet 40 formed of other materials such as conductive tape.

The thickness of the graphite sheet is preferably 0.05 mm or more, more preferably 0.07 mm or more, preferably 0.5 mm or less, and more preferably 0.2 mm or less. If the thickness of the graphite sheet is too small, the graphite sheet becomes easily damaged, and if the thickness is too large, the graphite sheet narrows the internal space of the case 10 for accommodating the power generation element 20, making it possible to accommodate the power generation element 20. This is because the volume (thickness) of is reduced.

In this way, by providing the conductive sheet 40, which has higher flexibility than the conductive plate, that is, is easily deformed, the pressing force of the spring piece 33 of the above-described conductive plate 30 is applied to the power generation element 20 more uniformly. This can prevent damage to the power generation element 20 and stabilize the electrical connection. Additionally, the conductive sheet 40 may be disposed between the electrode layer 21 and the bottom portion 111 of the concave container 11, as shown in FIG. 6 . As a result, it is possible to further prevent damage to the power generation element 20 and stabilize the electrical connection.

(Fourth Embodiment)

Next, the electrochemical element 1 of the third embodiment will be described in detail using FIG. 19. In the electrochemical device 1 of the present embodiment, the description of the same structure as that of the electrochemical device 1 of the first and second embodiments is basically omitted, and only the electrochemical device 1 of the first and second embodiments is described. Only a configuration different from that of the electrochemical device (1) will be described.

The electrochemical element 1 of this embodiment accommodates a flat element 50 in the internal space of the case 10. As shown in Fig. 7, the flat element 50 has an external can (electrode terminal) 51, a sealed can (electrode terminal) 52, the power generation element 20 described above, and a gasket 53. .

The external can 51 includes a circular flat portion 511 and a cylindrical side wall portion 512 continuously formed from the outer periphery of the flat portion 511. The cylindrical side wall portion 512 is provided to extend substantially perpendicular to the flat portion 511 when viewed in longitudinal section. The external can 51 is made of a metal material such as stainless steel. The external can 51 is disposed on the bottom 111 side of the concave container 11.

The sealed can 52 includes a circular flat portion 521 and a cylindrical peripheral wall portion 522 continuously formed from the outer periphery of the flat portion 521. The opening of the sealed can 52 faces the opening of the external can 51. The sealed can 52 is made of a metal material such as stainless steel. The sealed can 52 is disposed on the cover material 12 side. A power generation element 20 is accommodated between the external can 51 and the sealed can 52. Accordingly, the external can 51 functions as an electrode terminal connected to the conductor portion 113, and the sealed can 52 functions as the other electrode terminal connected to the conductive plate 30.

After the external can 51 and the sealed can 52 accommodate the power generation element 20 in the internal space, the cylindrical side wall portion 512 of the external can 51 and the peripheral wall portion 522 of the sealed can 52 ) is caulked with a gasket 53 in between. More specifically, the outer can 51 and the sealed can 52 have the openings of the outer can 51 and the sealed can 52 facing each other, and the cylindrical side wall portion 512 of the outer can 51 After the peripheral wall portion 522 of the sealed can 52 is inserted into the inside, the can is caulked with a gasket 53 interposed between the cylindrical side wall portion 512 and the peripheral wall portion 522. As a result, the internal space formed by the external can 51 and the sealed can 52 is in a sealed state. That is, the external can 51 and the sealed can 52 are exterior materials that enclose the power generation element 20 in their internal space. In addition, the outer can 51 and the sealed can 52 are not limited to a circular shape when viewed from the top, but can have various shapes such as an elliptical shape or a polygonal shape.

The gasket 53 is made of a resin material such as polyamide resin, polypropylene resin, or polyphenylene sulfide resin. Additionally, the method of sealing the internal space formed by the outer can 51 and the sealed can 52 is not limited to caulking through the gasket 53, and may be accomplished by other methods. For example, the cylindrical side wall portion 512 of the outer can 51 and the peripheral wall portion 522 of the sealed can 52 may be joined by interposing a heat-meltable resin or adhesive to seal the can. .

After the flat element 50 is accommodated inside the concave container 11, the conductive plate 30 is placed on the upper surface of the flat element 50 and is supported by locking the supported portion 31 to the support portion 115. I order it. At this time, the spring piece 33 of the conductive plate 30 is bent in a direction opposite to the flat element 50 while in contact with the flat portion 521 of the sealing can 52. The spring piece 33 presses the flat element 50 in the direction of the bottom 111 of the concave container 11 by its elastic force. As a result, the conductive plate 30 is in more stable contact with the flat element 50 without being displaced due to vibration or the like, and, similarly to the electrochemical element 1 of the first embodiment described above, is not subject to displacement due to vibration or the like. Good electrical connection can be maintained without misalignment.

In the electrochemical element 1 of the present embodiment, although not specifically shown, the porous metal layer 24 or the conductive sheet 40 described above may be disposed between the flat element 50 and the conductive plate 30. do. Additionally, the porous metal layer 24 or the conductive sheet 40 may be disposed between the flat element 50 and the bottom 111 of the concave container 11.

The flat element 50 is not limited to an all-solid-state battery having a solid electrolyte layer, and may be a non-aqueous electrolyte battery such as a lithium ion secondary battery, a battery having another flat shape, or a capacitor such as a lithium ion capacitor.

In the first to fourth embodiments described above, the electrode layer 21 functions as a positive electrode layer and the electrode layer 22 functions as a negative electrode layer. However, the electrode layer 21 functions as a negative electrode layer and the electrode layer 22 It may function as a negative electrode layer. In this case, the external terminal 13 functions as a negative terminal, and the external terminal 14 functions as a positive terminal.

In the fourth embodiment described above, the flat element 50 is accommodated in the inner space of the case 10 so that the external can 51 is disposed on the bottom 111 side of the concave container 11. The sealed can 52 may be accommodated so as to be disposed on the bottom 111 side of the concave container 11. That is, the flat element 50 may be accommodated in the internal space of the case 10 with the top and bottom of the flat element 50 shown in FIG. 6 turned upside down.

In the first to fourth embodiments described above, the power generation element 20 is composed of a laminate of the electrode layer 21, the electrode layer 22, and the solid electrolyte layer 23, but as the isolation layer, the solid electrolyte layer ( 23) Instead, a separator (not shown) is provided, and the electrolyte solution is accommodated together with the power generation element 20 in the internal space of the case 10, so that the electrochemical element can be used as a lithium ion secondary battery, lithium ion capacitor, or electric double layer capacitor. etc. can be done. In this case, the separator and electrolyte are those normally used in lithium ion secondary batteries, lithium ion capacitors, or electric double layer capacitors. Additionally, the electrode layer 21 and the electrode layer 22 may be replaced with a mixture layer of a positive electrode and a negative electrode normally used in various electrochemical elements 1.

In addition, according to the present invention, it is possible to contribute to Goal 7 "Making energy clean and accessible to all" and Goal 12 "Responsibility for creating and using responsibility" of the Sustainable Development Goals (SDGs) proposed by the United Nations.

(Example)

[Evaluation of vibration resistance]

An electrochemical device (all-solid-state battery) shown in FIG. 9 was manufactured using a conductive plate made of SUS304-CSP with a thickness of 0.2 mm. For the electrochemical device of this example, a vibration test was performed as follows to evaluate vibration resistance.

A test was conducted in which sinusoidal vibrations were sequentially applied to the electrochemical device of the example in three directions: vertical, horizontal, and high. The sweep of the sine wave was a logarithmic sweep that went back and forth between 7 Hz and 200 Hz for 15 minutes while changing the frequency, and the sweep was repeated 12 times in each of the three directions. Additionally, between 7 Hz and 18 Hz, the sweep is performed so that the peak acceleration is maintained at 1G, and from 18 Hz, the sweep is performed up to a frequency (approximately 50 Hz) at which the peak acceleration reaches 8G while maintaining all amplitudes at 0.8 mm. Additionally, up to 200 Hz, a sweep was performed so that the peak acceleration was maintained at 1G.

For the electrochemical device in the example where the vibration test was performed, the alternating current impedance at 1 kHz was measured at an applied voltage of 10 mV and compared with the value of the alternating current impedance measured before the vibration test, but no change was recognized, and the concave container It was confirmed that good electrical connection was maintained by the conductive plate fastened to the side wall.

[Evaluation of sealability]

Separately from the seismic test, the sealability of the case of the electrochemical element of the example was confirmed by the “helium leakage test method” (bombing method) described in JIS-Z2331. After putting the electrochemical element in the tank and pressurizing it with helium gas for 2 hours, the area around the electrochemical element in the vacuum chamber was evacuated for 1 minute to determine the amount of helium gas leakage. After 10 minutes, the amount of leakage was 1 × 10 ^- It was confirmed that it was ¹⁰ Pa·m3/s or less and had excellent sealing properties.

Although the embodiments have been described above, the present disclosure is not limited to the above-mentioned embodiments, and various changes can be made without departing from the spirit thereof.

1 Electrochemical element
10 cases
11 Concave container
12 Cover material
13 external terminal
14 external terminal
15 seal ring
111 bottom
112 side wall
113 conductor
114 conductor
115 support
20 power generation factors
30 Challenge Edition
31 Sebum support
32 flat part
33 Spring
331 border
332 tip
40 challenge sheet
50 flat element
51 External can
511 flat part
52 sealed cans
521 flat part
53 gasket
A virtual axis
C virtual point
P center point

Claims (13)

A case having a concave container having a bottom and a side wall portion and a cover material covering an opening of the concave container;
A power generation element sealed in the case and having a first electrode layer disposed on the bottom side, a second electrode layer disposed on the cover material side, and an insulating layer disposed between the first electrode layer and the second electrode layer;
Provided with a conductive plate disposed between the power generation element and the cover material,
The first electrode layer is electrically connected to a first conductive path extending from the inside of the case to the outside,
The second electrode layer is electrically connected to a second conductive path extending from the inside of the case to the outside via the conductive plate,
The conductive plate includes a flat portion facing the power generation element and a spring portion that rises from the flat portion to press the power generation element toward the bottom of the concave container, and has a diameter greater than the power generation element when viewed from the top. It is secured to the side wall of the concave container in the outward direction,
An electrochemical element wherein a gap is formed between the conductive plate and the cover material. According to claim 1,
An electrochemical element, wherein the spring portion is cantilevered on the flat portion and has a spring piece that presses the power generation element toward the bottom of the concave container. According to claim 1,
The electrochemical element wherein the conductive plate has a plurality of spring portions that rise from the flat portion and press the power generation element toward the bottom of the concave container. According to claim 3,
An electrochemical element, wherein each of the plurality of spring parts is cantilevered and supported on the flat surface and has a spring piece that presses the power generation element toward the bottom of the concave container. According to claim 4,
An electrochemical element in which the spring pieces of the plurality of spring portions are each arranged to be line symmetrical or point symmetrical when viewed from the top. According to claim 4,
An electrochemical element in which the spring pieces of the plurality of spring parts are each arranged radially when viewed from the top. According to claim 2,
An electrochemical element wherein the spring piece is formed so that the width of the cantilevered support on the flat portion is wider than the width of the tip portion. According to claim 2,
An electrochemical element wherein the spring piece is formed such that the width of the tip portion is wider than the width of the cantilevered support on the flat portion. According to claim 2,
The spring piece is an electrochemical element that is a disc spring. According to claim 2,
An electrochemical element wherein the tip of the spring piece is bent in a direction opposite to the power generation element. The method according to any one of claims 1 to 10,
An electrochemical element, wherein the power generation element further has a porous metal layer on the surface of the second electrode layer. A case having a concave container having a bottom and a side wall portion and a cover material covering an opening of the concave container;
an exterior material encapsulated in the case and including a first electrode terminal disposed on the bottom side and a second electrode terminal disposed on a side of the cover material, and an exterior material sealed inside the exterior material, the first electrode layer, the second electrode layer, and the A flat element having a power generation element including an isolation layer disposed between a first electrode layer and the second electrode layer,
Provided with a conductive plate disposed between the flat element and the cover material,
The first electrode terminal is electrically connected to a first conductive path extending from the inside of the case to the outside,
The second electrode terminal is electrically connected to a second conduction path extending from the inside of the case to the outside via the conductive plate,
The conductive plate includes a flat portion facing the flat element and a spring portion that rises from the flat portion to urge the flat element toward the bottom of the concave container, and has a diameter greater than that of the flat element when viewed from the top. It is secured to the side wall of the concave container in the outward direction,
An electrochemical element wherein a gap is formed between the conductive plate and the cover material. According to claim 12,
An electrochemical element, wherein the spring portion is cantilevered on the flat portion and has a spring piece that presses the flat element toward the bottom of the concave container.